Process of reducing compounds with electrically-developed heat.



. port ons.

ITED STATES ILXTEXT OFFICE.

FRANK .T. TONE, 0F NIAGARA FALLS, NEW YORK.

Specification of Letters Patent.

Patented Oct. 29, 1907.

Application filed September 22. 1908. Serial No. 335.704.

To all rrhom 1'! may cmtcrrn:

ilc it known that l, Flt-\XK .l. Ton of Xingam Falls. N agara county. Ken York. have invented a. new and Improved Process for Reducing ('ontpottntls with lilectrically-Developeil Heat. oi which the following is a specification.

This imcnti n relates to the production of silicon in its elemental lorm.

in the 1irnct350- ltQRBlUitnl'O described for the production of silicon it is usual to employ a mixture of carbon and silica of proportionsisubstantially according to the equation SiO,+2(-=Si+2ll(l. \Vhen using this mixture the evolution of (0 gas is rapid and tends o carry with if. from the furnace a certain quantity of vapor of the silicon. thus lowering the output of metal and the efficiency of the process. I hayediscovered thaiif a compound oi silicon, oxygen and carbon is taken in whichthe silicon is already partially reduced and to this suflicient SiO, in added so that the total combined oxygen content of the mixture is satisfied by the carbon in the mixture for conversion into (Ov the etlicicncy oi the process is greatly increased and that the output is. much larger for a given expenditure of power.

Silicon. carbon and oxygen combinein various protaining 55 to 65 per cent. silica and the rcmniuder carbon, is heated in an electric furnace at the lou'cst. temperature at which combination talccs place and reduction of silica begins, the product contains compounds of it It when this partially roducc -mntorial is used as a constituent'ol' the charge mixtu're t'orthe p'rmlnction ofsilicon, i have found it prel'ornhle toudd Sit); in slight exr'msol'that required for the cotnplctc onversion of all the carlmn and oxygen into ('0. in order to coutpcnsutu of! n ccrtuiu amount of Sil l volatilixcd. hcproporlions l have found to work oll in practiccv are 44 parts of Sin, and 6 parts of the silicon-carlmu-oxygcn compound hcrctol'oro described. which 1 place in an electrical furnace prcl'orahly such as dcscribod in my priorpatcnt No. 74-Ll22. dutcd Km. 24. I903, where 1 anojcct it t thcactiun of electrically developed heat. and

When a mixture of silica .md carbon conl l 1 l l l l l reduce the silicon oelcmcntal form as therein described. The amount of ('0 gas evolvcd in the completion of the reaction is much less per unit of reduced silicon than ollen using a mixture of ilica and carbon. This results in the reaction proceeding more quietly and in the loss by yolatilization of silica and silicon being smaller.

i do not limit. myself So the silicon-mrbon-oxygen compounds lrUl'0lllf'9l'P dcscrihed. Such compounds vary in comporzit ion. and any of them in which the SiO, is in a llll rt iall rcduced state. such as siloxicon and the byproduct of the carhorundum process sometimes called white stuff will fulfil the requirements of the process.

lly material containing silicon in a partially reduced state I mean one in which the ratio of oxygen to silicon is less titan in Silk: and by compounds in a partially reduced state I mean the state in which they have given up part but not nllot' their oxygen.

I claim:

l. 'lhc lll'oi'css of producing silicon, which consists in snbjccting a mixturc containing silica and a compound containing silicon. on gun and l'fll'lltlll to olcctrlcnlly 'dcvcluped hca and rcducng tlusilicon thcrchy to its clcmcntal form.

lluplnt't s or rcducing silicon from its orcs, which consists in tit-st Mtl jcctlng :1 mixture of carbon and silimutcrlnl to electrically tlcvclopcd heat sutlicicnt to II rolncc the silica. tin-n mixing tlnsilicon-curmul ltl'ctlllt'l so forntctl with n furtlur quantity of silica :zml su njccliug :utltl mizzlurc to clcctt'knlly devclopcd hcat sullicicnr to cotnplctcly rcduco thc silicon to its filt'lllcllllll form.

fl. 'l'hc proccss of rctlucing to thclr clcuicntal form. oxyc n t'ulnpoulul.-: having tlu propcrty. whcn in a partially fiduccd stutc, of forming wcll-dclincd compounds with curl-on. which consists in \Illljtt'llllfJ u mixture containin nu oxid of thc clcmcnt and a compound l'ln llllll}: l'coln purllnl rcduction ct thc oxygcn compound uilli carbon. nud containing lhc clcmcnt with oxygcn und cnrlxou, to clccll'lt'JllY d vclcpc'l hcnlfnnd rmluclug nuid clcuu-nt thcr by to ll: clcmcntnl form.

t. 'l'hc process of rc'lucing to thclr clcmcntnl iorln. oxyt-n compounds having tlupropc \vhcn in a partially re duccd statc. of I'm-min m-lj d'cllnetl compounds with cur hon. which conslsts in llt'st' ihjcctliig n llliXllll't' of cnrhon and thc uYyg-Hl compound fh clcclrlcnlly dcvclo wd hunt sulli icnt to partially rmhicc it and form a product containing cut-hon. oxygcu and tlic compound. thcn mixing the llllJl H'l -m fol'luod with n further quantity of ill! conipouud and suhjcctiu: said mlxtnrcto clcctricully dcu-lopcd Etcul Hllllllltlll to complcl y reducethc compound to its 166 clcnu-ntnl form. ln lcsllllluhy whcrcof, l .lun'c lwrctmlo H't my hand.

FICA N K J. TON E.

Wit ncsNcs An'rnttk Ln-rs. L. 1,. Drum-2n. 

